Automatic regulator for stokers



p 29, 1931- D. o. MILLER 1,825,279

AUTOMATIC REGULATOR FOR STOKERS Filed May 28, 1928 uvemtoz 3 51;, wW/WPatented Sept. 29, 1931 UNITED STATES DALE O. MILLER, 01 DETROIT,MICHIGAN AUTOMATIC REGULATORIOR STOKERS Application filed May 28, 1928Serial No. 281,824.

This invention relates to stokers and more particularly to improvementsin the regulating means for hydraulic stokers.

It is one of the primary objects of this invention to automatically varythe speed of the hydraulic motor for actuating the stolrer in accordancewith variations in the load on the furnace.

Another object of this invention is to provide regulating means of theabove character capable of operation independent of the fluid supplypump and actuating means therefor so that the pump may be run at aconstant speed.

The invention further contempates an arrangement whereby the draftinducing means and damper are controlled by the regulating means.

Other objects, advantages and novel de- 7 tails of construction of thisinvention will be made more apparent as this description proceedsespecially when considered in connection with the accompanying drawingswherein:

Figure 1 is a perspective view of a Stoker embodying my invention;

Figure 2 is a sectional detail view of the automatic regulating valve.

In general there is illustrated in Figure 1 30 of the drawings, a steamboiler 10 fired by an underfeed stoker 11. The latter is preferably ofthe reciprocating type, having a ram for feeding the coal from thehopper into the furnace in accordance with the usual prac- 35 tice. Theram or coal feeder illustrated herein is operated by a suitablehydraulic motor 12. The fluid for operating the motor is derived from aconventional pump 13 and the normal flow of the fluid is through theconduits 14, motor 12, outlet conduit 15, conduit 16 to the reservoir 17and down through the standpipe 18 back to the pump.

For controlling the amount of fluid admitted to the hydraulic motor 12to thereby regulate the frequency of operation of the ram or coalfeeder, I provide a 'by-pass 19 connected at one end to the deliveryside of 50 the pump and at the other end to the reservoir 17. Arrangedwithin the by-pass 19 is a suitable valve 20 having an operating lever21 disposed between the adjustable stops 22. Connected to the operatinglever 21 by means of the cable 23 is a suitable expansible chamber ordamper regulator 24 operated by the steam pressure from the pipe 25 andset for operation at any predetermined boiler pressure. As will beapparent from Figure 1 of the drawing the cable 23 is provided withextensions 26 and 27 connected to the 0'; damper 28 and louver 29respectively, the arrangement being such that the expansible chamber inaddition to controlling the speed of the hydraulic motor, regulates thedamper 28 and the amount of air furnished to the furnace for combustion.The louver 29 and damper adjustments are effected simultaneously and inaccordance with the adjustment of the hydraulic motor so that the properdraft will be furnished the furnace at all times. p

The air for combustion is furnished by a fan 30 driven by any suitableprime mover as for example, the electric motor 31 whichas shown alsodrives the pump 13. The out 75' let for the fan being through a suitableoutlet box 32 communicating with the interior of the furnace in thecustomary manner and. controlled by the louver 29. 1 a

In order to effect a manual adjustment of the hydraulic motor I providea bypass 33 extending around the valve 20 and'connecting into the pipe19. This by-pass is controlled by a suitable manually operated valve34:. Thus it will be apparent thatth'e '85 by-pass 33 functions as afixed by-pas's capable of' effecting a change in speed offthe hydraulicmotor independent of the-steam pressure. It will further be noted thatthis latter arrangement, as well as the automatic regulating meanshereinbefore set forth is capable of varying the speed of the hy draulicmotor independent of the driving means'31. In other words with thepresent invention, the speed of the ram orcoal feeder may be variedproportionate'to the load without varying the speed of the motor 31. i

For controlling the pressure of the motor operating fluid a suitablepressure relief valve 35 is provided in the pipe 36 which,

as, shown communicates at one end with the supply pipe lei and at theopposite end with the reservoir 17, the arrangement being such that iffor any reason the stoker is stalled the pressure built up by the motoroperating fluid in the pipe lei will cause the valve 35 to open andpermit the fluid to escape into the reservoir.

Referring now to the operation, it will be noted that whenever the steampressurerises the expansible chamber 2-1 is expanded thereby opening thevalve 20 and allowing a larger amount of fluid to by-pass through thepipe 19 back to the reservoir 17 and con sequently reducing the speed ofthe hydraulic motor 12 proportionate to the amount of fluid by-passed.On the other hand, when the steam pressure is lowered, the chamber iscontracted, thus closing the VZLlX'G 20 and increasing the amount offluid pumped through the hydraulic motor 12 and consequently increasingthe speed of the hydraallic motor and the amount of coal forced into thefurnace. In this connection it will be noted that at the same time thespeed of the hydraulic motor is increased the louver 29 is openedsupplying more air for combustion to take care of the extra fuel fedinto the furnace. The damper 28 is also opened to permit the exhaustgases to escape through the stack.

Having thus revealed this invention, I claim as new and desire to securethe following combinations by Letters Patent of the United States.

What I claim as my invention is:

1. In combination, a furnace having a Stoker, a fluid opera-ted motorfor actuating said stoker, a pump for supplying fluid directly to saidmotor, means for by-passi-ng the fluid to reduce the speed of the motor,and pressure responsive means automatically operable upon fluctuationsin the load on thedfurnace for actuating the means aforesal 2. In asteam boiler having a furnace therefor the combination of a stoker forsaid furnace, a fluid operated motor for operatingsaid stoker, a pumpfor supplying fluid directly to said motor, valve means for bypassingthe fiuid to reduce the speed of the motor, pressure responsive meansconnected to the steam boiler and automatically operable according tothe pressure within the boiler and means connecting .the pressureresponsive means and the valve means whereby the valve means iscontrolled by the pressure responsive means.

3. In combination, a furnace having a Stoker, a fluid operated motor foractuating the stoker, a pump for supplying fluid to said fluid motor,draft inducing means for the furnace including a fan, a constant speedpower means for actuating both said fan and said pump, means forcontrolling the ture.

DALE O. MILLER.

